Prediction of springforward in continuous-fibre/polymer L-shaped parts

Continuous-fibre-reinforced thermoset laminates that are cured hot, exhibit deformations due to cure and thermal shrinkage. When L-shaped composite components are released from the mould after cooling to ambient temperature, a decrease of the enclosed angle is observed. This is referred to as the springforward phenomenon. The main cause of springforward, the mismatch in thermal expansion along and across the fibres, cannot explain totally the springforward found in experiments. Three other possible influences on springforward were investigated: an inhomogeneous fibre/matrix distribution through the thickness, an inhomogeneous heat distribution during the cure cycle and the difference in thermal expansion between the mould and the composite component. Finite element results show that the springforward is affected significantly by the amount of cure shrinkage and by the difference in thermal expansion between the mould and the composite component.